1. Field of the Invention
The present invention relates to a machine for harvesting maize, designed to be applied to the front part of a combine harvester.
2. Description of the Related Art
Machines for harvesting maize of the most widespread type comprise a supporting structure designed to be fixed to the thresher and carrying a plurality of harvesting units set alongside one another in a transverse direction. Each harvesting unit is dedicated to the harvesting of a row of maize plants. Each harvesting unit usually comprises a fixed framework carrying two stripper plates. Said stripper plates have respective edges facing one another that form a squeezing channel for the maize stalks. Each harvesting unit comprises a pair of counter-rotating traction rollers arranged underneath the squeezing channel. The traction rollers grip the maize stalks and draw them downwards, passing the stalks between the facing edges of the stripper plates. The cobs of maize come into contact with the top surfaces of the stripper plates and are detached from the stalks as a result of the stalks being drawn down by the traction rollers. The cobs gather on the top surface of the stripper plates and are conveyed towards the thresher by gathering chains located on top of the stripper plates.
In order to ensure a high productivity, the maize stalks are drawn downwards at a high speed. This leads to a high-speed impact of the cobs against the top surfaces of the stripper plates.
One drawback of this type of machine is that the impact of the cobs on the stripper plates causes a detachment of the grains of maize from the cores of the cobs. This problem becomes particularly sensitive when harvesting very dry maize. On the one hand, the harvesting of dry maize is very advantageous since it avoids a successive drying step after harvesting. On the other hand, in the case of dry maize, the grains detach easily from the core and the impact of the cobs at high speed on the stripper plates leads to a loss of useful crop on account of the removal of the grains from the cobs.